Phylum Arthropoda
Subphylum Crustacea
Class Malacostraca
Order Isopoda
Family Cirolanidae

Bahalana yagerae (Carpenter, 1994)

Bahalana yagerae: after Botosaneanu & Iliffe, in prep.

Synonyms: Dodecalana yagerae Carpenter, 1994

Taxonomic Characterization: Unique in the suborder Flabellifera in that adults have six pairs of legs (pereiopods), rather than seven - a clear case paedomorphy. Eyes absent. Distinctive characteristics include long projections on pereiopods 1-3, setae on pleopod endopods 1-5,and absence of retinacula on maxillipedal endites. Possess microscopic orange-colored crystals in the connective tissue surrounding several pereional organs. The mandibular molar process bears fine setae rather than teeth. Pereiopod 1 is prehensile, while pereiopods 2 and 3 are ambulatory. Originally placed in the new genus Dodecalana by Carpenter (1994), but now considered to belong to Bahalana (Botosaneanu & Iliffe, 1997:93).

Ecological Classification: Stygobitic

Size: Males range in length from 3.7-9.1 mm; females from 5.6-11.3 mm

Number of Species in Genus: Five, all stygobitic

Genus Range:

Species Range: This is the most widely distributed species of the genus Bahalana, occurring on both the Little Bahama and Great Bahama Banks which are separated from one another by a deep water channel.  Originally reported from anchialine caves on Grand Bahama Island and adjacent Sweeting's Cay, Little Bahama Bank (Botosaneanu & Iliffe, 1997).  Subsequently, one female was collected from the "New Room" located about 1500 m into Conch Sound Blue Hole, an ocean blue hole on the northern end of Andros Island, Great Bahama Bank (Botosaneanu & Iliffe, 2002).  Other locations for B. yagerae reported in this latter paper include Janet Pyfrom's, Virgo and Sagittarius Blue Holes and Lucy's Cave, all at Sweeting's Cay; and Basil Minn's Blue Hole on Great Exuma Island.

Closest Related Species: Bahalana geracei and Bahalana exumina

Habitat: Anchialine limestone caves

Ecology: Collections from Lucayan Caverns were from below the halocline at a depth of 21 m in fully marine salinity waters (35 ppt) where dissolved oxygen concentration was 0.05 ppm. Other inhabitants of this cave include remipedes, hadziid amphipods, thermosbaenaceans, and the cave fish Lucifuga.  The far interior of Conch Sound Blue is the first non-anchialine, ocean blue hole location for the species (Botosaneanu & Iliffe, 2002).

Life History: Little behavioral information is known. Mature males have stylets on pleopod 2, well-developed penes on pereionite 7, and many sperm packed into the penes and vas deferentia. However, no oostegites are developed on the females, but this is not unusual from stygobitic cirolanids (Carpenter, 1994).  The female from Conch Sound Blue Hole had at least 16 large eggs (Botosaneanu & Iliffe, 2002).  Small to very small specimens from Sagittarius Blue Hole were nevertheless fully developed and with 6 pereiopods.

Evolutionary Origins: The family Cirolanidae is considered the most primitive of the families of the suborder Flabellifera. It is thought that stygobitic cirolanids were stranded when high sea levels receded, either during the Cenozoic Era (55 million years ago) or during the Late Cretaceous Period (135 million years ago) (Carpenter, 1981). All five species in the genus Bahalana are found in the Bahamas archipelago.  Speciation in Bahalana was very probably a rather recent event.

Conservation Status: Known from three anchialine caves on Grand Bahama Island, five anchialine caves on adjacent Sweeting's Cay, one anchialine cave on Great Exuma Island and one marine cave on Andros Island.

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